3D Keyer.

The main eyedropper defines the initial screen-color range; adjacent tools add samples to or subtract them from the current range. On the Edit page, onscreen sampling uses the Open FX overlay. Several genuinely different screen regions are safer than one long stroke crossing mixed lighting.

CheckDo not cross foreground detail with a stroke; delete a bad stroke or Reset and rebuild when the sample is compromised.

Invert swaps the opaque and transparent sides of the existing key. It does not improve sampling or clean gray edges; it only reverses matte meaning.

CheckAfter Invert, verify Alpha Highlight B/W and the downstream composite.

Stroke addresses stored sampling paths; Delete Stroke removes the selected path, while Reset clears sampled colors while retaining the general control setup. This is safer than compensating for a bad sample with extreme adjustments.

CheckAfter changing Color Space, compare from a clean sample instead of carrying an old accumulated range forward.

Color Space sets the representation used to evaluate the keyed color range. YUV is shown in the capture; HSL, HSP and Lab provide alternative separation geometry when screen and foreground overlap poorly in one representation.

CheckChanging Color Space is a reason to rebuild the sample, otherwise the comparison mixes two models with one stale selection.

Soft gives a gentler falloff around the sampled range; Flat is a practical green/blue-screen starting behavior; Tight stays closer to the exact sampled color; Luma shifts the task toward luminance separation. These are behavior models, not four finished quality presets.

CheckIf luminance separation is doing the work, consider whether Luma Keyer is the clearer specialized tool.

Despill suppresses screen-color contamination in foreground RGB, especially on hair, skin, translucent fabric and reflections. It belongs to composite color, not alpha geometry.

CheckStabilize the matte first. Excessive Despill can gray edges and remove legitimate green or blue subject color.

Show Paths keeps sampling paths visible in the Viewer. Smart Show Paths displays a path while drawing and hides it after the stroke, keeping the Viewer cleaner during repeated sampling.

CheckThis is diagnostic display state, not matte processing. Use paths to find accidental strokes crossing the foreground.

Auto B/W Highlight automatically presents black-and-white alpha during sampling so the effect of a new stroke can be judged immediately. It is enabled in the capture.

CheckGray matte values are not automatically wrong: hair, motion blur and transparency can legitimately be semi-transparent.

Show Key Map visualizes the selection in a color/brightness map; Key Map Zoom enlarges that diagnostic map rather than the image or matte. The capture shows Show Key Map off with Zoom at 0.500.

CheckUse the Key Map when Tolerance/Shift/Rotate feel blind; it helps reveal what is actually moving in the selection.

Chroma Tolerance expands or contracts the accepted color volume around sampled colors. Raise it in small steps while viewing Alpha Highlight B/W: the goal is to cover screen variation, not every similar foreground hue.

CheckIf Tolerance must become very large, add a clean sample or reconsider Color Space/selection geometry instead of expanding endlessly.

Chroma Softness defines the transition around the Tolerance boundary. Adaptive Chroma Softness helps keep behavior consistent across saturated and desaturated areas; it is enabled in the capture, with Chroma Softness shown at 25.0.

CheckSoftness helps hair and motion blur, but an overly wide transition makes foreground alpha gray too far inside the true edge.

Tilt, Shift and Rotate reposition or orient the existing chroma selection instead of uniformly widening Tolerance. This is useful when a screen cluster is stretched by mixed light, tint or camera response.

CheckMake small changes with Key Map or B&W preview. Large geometric corrections often indicate a poor sample or unsuitable Color Space.

Luma Low and Luma High set luminance boundaries, while Low/High Softness control the transitions at those boundaries. They can reject very dark or bright regions that resemble the screen in chroma without widening the color tolerance.

CheckDo not remove legitimate semi-transparent detail merely to make a perfectly binary matte. Check the result on the replacement background.

Pre Filter can stabilize compression chatter and fine chroma noise before later matte processing. The capture shows 0.200. It is not general image denoising; too much filtering removes hair and edge texture before cleanup.

CheckUse the minimum needed value and inspect fine detail at 100% viewer scale.

Clean Black gently pushes gray contamination in the background matte toward black. It is the first choice for weak speckle or holes on the transparent side before hard Black Clip.

CheckIf hair or motion blur disappears, revisit sampling or Key Adjustments instead of increasing cleanup further.

Clean White gently strengthens gray regions inside the foreground matte toward denser white. It is useful for small holes in the opaque subject core but should not turn legitimate transparency into solid alpha.

CheckJudge hair, glass, motion blur and translucent fabric separately from the opaque core.

Black Clip and White Clip hard-collapse remaining alpha gradations toward black or white. The capture shows Black Clip at 0.0 and White Clip at 100.0—a starting state that preserves maximum gradation.

CheckLeave clipping until after Clean Black/White. It can quickly destroy fine hair, translucent edges and motion blur.

Blur Radius softens the already-built alpha, while In/Out Ratio biases that edge treatment inward or outward. Their job is to match the digital edge to the shot optics, not to hide poor sampling.

CheckToo much blur creates a halo. Judge it over the actual replacement background, not only in the B&W matte.

Garbage Matte provides a coarse spatial constraint. None adds no constraint; Rectangle and Ellipse are useful when stands, screen edges or set pieces outside the subject should not be solved by color.

CheckGarbage Matte does not repair the edge inside the retained region and does not replace a tracked Power Window for complex moving constraints.

Alpha Highlight keeps image context while exposing transparency; Alpha Highlight B/W displays the matte directly; Final Composite returns the result over the underlying image. These serve three distinct jobs: color/edge diagnosis, alpha diagnosis and final composite judgment.

CheckDo not finish a key from Final Composite alone: inspect the B&W matte first, then return to the beauty image for Despill and edge integration.